Steam generating system



My 22, 1934. c LUCKE 1,959,794

STEAM GENERATING SYSTEM Original Filed Aug. 11, 1928 2 Shets-Sheet l FlE -j INVENTORY m am Patented May 22, 1934 1,959,794 STEAM GENERATING SYSTEM Charles E. Lucke, New York, N. Y., assignor to The Babcock & Wilcox Company, Bayonne, N. J., a corporation of New Jersey Application August 11, 1928, Serial No. 298,998 Renewed October 17, 1933 8 Claims.

This invention relates to a steam generating system in which a fuel fired steam boiler generates steam. High pressure steam from the fuel fired boiler may be used to generate steam in a steam heated raw water boiler at a lower pressure. A part of the steam from the fuel fired boiler may also be used to drive a turbine. Provision is made for drawing off concentrated water from the high pressure fuel fired boiler before scale forms and the blow-oil water is delivered preferably continuously to the low pressure boiler circulation. Some or all of the low pressure steam is fed to a low pressure stage of the turbine and its condensate is added to that from the high pressure boiler with its turblue and delivered to a surge tank. Any excess of pure water in the surge tank over what the high pressure boiler can take is introduced into the low pressure boiler.

The invention will be understood from the description in connection with the accompanying drawings in which Fig. 1 is a somewhat diagrammatic view showing thesystem, and Fig. 2 is a side view on an enlarged s cale showing some of the details of the steam low pressure heated boiler.

In the drawings, reference character 1.indicates a furnace above which is illustrated a boiler of the Babcock & ,Wi1cox type having a steam and water drum2- and a superheater 3. A valved outlet 4 leads from the superheater to the high pressure stage 5 of a turbine. A valved outlet 6 leads from the steam space of the steam and water drum 2 tea drum or manifold '7, from which valved pipes 8 and 9 lead the high pressure steam to headers 10 and 11 that are connected by tubes 12., Tubes 13 that are longer than the tubes 12 extend throughthetubes 12 and headers 10 and 11, and are connected to headers 14 and 15. A valvedblow-off pipe 16 leads from the water space of the steam and water drum 2 to a manifold 1'7, from which manifold nipples 18 lead to the lower end of the headers 14. Valved pipes 19 and 20 lead from a steam and water drum 21 to the headers 14 and 15. A steam outlet pipe 22 leads from the steam space of the steam and water drum 21 to a T- 22 from which a valved pipe 23 may lead to a place of use of the'steam, such as steam for process work, for example. A valved pipe 24 also leads from the .T 22' to a low pressure stage 24' offthe turbine. A condenser 25 is proivided for the turbine exhaust and a pum 26 forcesthe condensate from the condenser 25 into'fthe surse tank 27. An overflow pipe 28 leads from surge 27 to the feed water A pump 31 forces raw feed water is forced through the pipe 35 into the steam and water drum 2.

Nipples 36 lead from the headers 11 to the manifold 37 that is provided with a valved pipe 38, through which uncondensed gases may be removed. A valved pipe 39 leads from the manifold 37 to a pump 40 by means of which condensate is returned through the pipe 41 to the pipe 35 and thence to the steam and water drum 2.

The operation is as follows: Feed water that contains very little, if any, impurities is introduced through the pump 34 into the drum 2 of the high pressure fuel fired boiler so that the danger of the tubes becoming scaled and burned out is decreased or entirely removed. Also, if foul water becomes accidentally introduced into the high pressure boiler, the water containing concentrated impurities is withdrawn through the blow-off pipe 16 before it becomes sufficiently concentrated to deposit the impurities, such as scale. The blow-off water passing out through the pipe 16 is utilized in the low pressure boiler and low pressure steam is generated therefrom. High pressure steam from the fuel fired boiler passes through the pipe 6 to the manifold 7, and thence through the pipes 8 and 9 into the annular spaces between the tubes 12 and 13, thus heating the tubes 13 and becoming condensed. The condensate is returned to the boiler by means of the pump 40. Raw feed water from the tank 29 is forced by means of the pump 31 into the steam and water drum 21 of the low pressure steam heated boiler and passesthrough the pipes 20 into the headers 11, thence through the tubes 13 where evaporation takes place. The mixture of steam and water passes through the headers 14 and pipes 19 into the steam and water drum 21. The steam from the steam and water drum 21 that passes through the pipe 24 into the turbine is condensed in the condenser 25 and also the steam that passes through the pipe 4 into the turbine 5 is condensed in this condenser and as much of the condensate as is needed for feed water from the high pressure fuel fired boiler is fed into that boiler from the surge tank 27 by means of the pump 34.: through the pipe 35. The excess condensate passes through the overflow pipe 28 and is returned to the low. pressure steam heated steam boiler. In this way the impurities are all restricted to the low pressure steam boiler and become deposited only in the tubes 13, which may be readily cleaned through handholes that are provided in the headers 14 and 15 by ordinary means such as the well known turbine tube cleaner. The scale can be removed by isolating one pair of headers 14 and 15 by closing valves in their drum connectingnipples, without stopping the operation of the rest of the tube bank connected to other pairs of headers like 14 and 15.

In this manner, all scale deposits are kept out of the fuel fired boiler where tubes might be burned when scaly especially furnace Wall tubes, and scale is collected in the steam heated boiler where it can do no harm and from which it can be regularly removed without stopping operation by providing one pair of headers 14 and 15 more than is necessary for full capacity.

It is understood that without departing from the invention, steam from the low pressure boiler may be sent directly to the condenser without passing through the turbine, and that a separate condenser may be used to collect make-up con-- densate for the fuel fired boiler. Also, that the steam from the low pressure boiler may be used for heated process work, as in paper mills or district distribution of steam for heating buildings.

I claim:

1. A steam generator combination including a combustion heated high pressure boiler, and a low pressure boiler connected therewith being heated only by high pressure steam without intermingling of the fluids, means condensing steam from both of said boilers, means returning only condensate to the high pressure boiler whereby scale forming materials are maintained at a minimum, and means for furnishing raw water to the low pressure boiler.

2. A steam generator combination including a combustion heated high pressure boiler, and a low pressure boiler connected therewith being heated only by high pressure steam without intermingling of the fluids, means condensing steam from both of said boilers, means returning only condensate to the high pressure boiler whereby scale forming materials are maintained at a minimum, means for furnishing raw water to the low pressure boiler, and means for conveying some of the water in the high pressure boiler to the low pressure boiler to thereby reduce the concentration of scale forming materials in the high pressure boiler while increasing the ability of the low pressure boiler to furnish make up condensate to the high pressure boiler.

3. A steam generator combination including a combustion heated high pressure boiler, and a low pressure boiler connected therewith being heated only by high pressure steam without intermingling of the fluids, means condensing steam from both of said boilers, means returning only condensate to the high pressure boiler whereby scale forming materials are maintained at a minimum, means for furnishing raw water to the low pressure boiler, and means for interrupting the operation of at least a portion of the low pressure boiler for cleaning without shut; ting down the high pressure boiler.

' 4. A steam generator combination including a combustion heated high pressure boiler and a low pressure boiler heated mainly by high presssure steam from said high pressure boiler without intermingling of the heating and heated fluids, means condensing steam from both of said boilers, means returning only condensate to the high pressure boiler, and means for furnishing raw water to the low pressure boiler.

5. A steam generator combination including a combustion heated high pressure boiler and a low pressure boiler heated mainly by high pressure steam from said high pressure boiler, means condensing steam from both of said boilers, means returning only condensate to the high pressure boiler, and means for furnishing raw water to the low pressure boiler only.

6. In a steam power plant, a combustion heated high pressure steam generator, a low pressure steam generator, means for passing high temperature steam from said high pressure generator to said low pressure generator for supplying substantially all the heat for the steam generating requirements thereof, steam utilizing and condensing means arranged to receive steam generated in said high and low pressure generators, means for supplying raw make-up water to said low pressure generator only, and means for supplying only the condensate of steam generated in said low and high pressure generators as feed water to said high pressure generator.

'I. In a steam power plant, a combustion heated high pressure steam generator, a low pressure steam generator, means for passing high temperature steam from said high pressure generator to said low pressure generator for supplying 115 substantially all the heat for the steam generating requirements thereof, steam utilizing and condensing means arranged to receive steam generated in said high and low pressure generators, means for supplying raw make-up water to 120 said low pressure generator only, means for supplying only the condensate of steam generated in said low and high pressure generators as feed water to said high pressure generator, and a blow-off connection from said high pressure generator to said low pressure generator.

8. In a steam power plant, a combustion heated high pressure steam generator, a low pressure steam generator, means for passing high temperature steam from said high pressure generator to said low pressure generator for supplying substantially all the heat for the steam generating requirements thereof, a common steam utilizing and condensing means arranged to receive steam generated in said high and low pressure generators, means for supplying raw make-up water to said low pressure generator only, and means for supplying only condensate as feed Water to said high pressure generator.

CHARLES E. LUCKE. 

